Electromagnet contactor



June 16, 1925.

C. H. HODGKINS ET AL ELECTROMAGNET CONTACTOR Filed F 20, 1920 3 Sheets-Sheet 1 C7 WORNEY June 16, 1925.

1,541,814 c. H. HODGKINS ET AL v ELECTROMAGNET CONTACTOR s Sheets-Sheet 2 Filed Feb, 20, 1920 Rs k/hMS WITNESSES:

ATTORNEY June 16, 1925.

c. H. HODGKINS ET. .AL 1

ELECTROMAGNET CONTACTOR Filed Feb. 20, 1920 3 Sheets-Sheet 3 a ja n 6 Y 5 0 W E m m .m

WITNESSES:

Patented June 16, 1925.

UNITED STATES PATENT OF F ICE. 1

CHARLES H. HODGKINS AND WALTER C. GOODWIN, F PITTSBURGH, PENNSYLVANIA,

ASSIGNORS TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A COR- PORATION OF PENNSYLVANIA.

ELECTROMAGNET CONTACTOR.

To all whom it may concern: Be it known that we. CHARLES H. Honc- KINS, a subject; of the King of Great Britain.

and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, and WAUI'ER C. Goonwm, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Electromagnet Contactors, of which the following is a specification.

Our invention relates to electromagnets and particularly to electromagnets employed foractuating electrical contactors and similar devices.

One object of our invention is to provide a silently-operating electromagnet that is adapted for use with alternating current.

Another object of our invention is to provide an improved form of electromagnet that shall be of simple and inexpensive construction.

A further object of our invention is to provide an electromagnet having a shading coil at each juncture of relatively movable parts included in the magnetic circuit of the electromagnet.

An additional object of our invention is to provide an improved bearing for the armature of the electromagnet.

In such electromagnets as have heretofore been provided, it has been found diflicult to secure uniform and proper seating of the armature members on the core members except by means of hand work. F urthermorc, it has been diflicult to )rovide a magnetic damping action at the plvotal mountings of the armatures of such electromagnets as heretofore have been provided in order to render the operation of the electromagnet silent.

According to our invention, we provide a member that may be easily machined to obtain uniform close engagement with the "core member and which has limited universal movement to ensure proper seating of the armature member on the core member. otherv features of our device are set forth in the specification.

- Fig. 1 of the accompanyin drawings is a side elevationalview, partial y in section on line I-I of Fig. 2, of a portion of an electromagnet contactor constructed in accord ance with our invention. Fig. 2 is a top Application filed February 20, 1920. Serial No. 360,202.

plan view of the contactor' shown in Fig. 1. Fig. 3 is a side view, partially in section on line III-J11 of Fig. 2 and partially in elevation, of the armature and the associated supporting member shown in Fig. 1. Fig. 4 is a top plan View, partially in section taken on line IV-IV of Fig. 3, of the armature and the armature-supporting member shown in Fig. 1.

Fig. 1 and Fig. 2 of the drawings illustrate a'pair of switches, each of which comprises a stationary contact member 1 and a supporting member 2 that is mounted on a panel 3. Movable contact members 4 of the respective switches are actuated into, and out of, engagement with the co-acting stationary contact members 1 by means of an electromagnet device The contactors 1 and 4 are provided with an arc shield 6, of familiar construction, which embodies a blowout coil 7 to energize magnetic side plates 8, and an arc splitter 9 that is mounted between the plates of the shield 6. A bolt 10, by means of which the contact-supporting member 2 is mounted on the panel 3, constitutes a terminal. member for the blowout coil 7 and the contactor 1. A terminal bolt 11 constitutes the remaining terminal for the blowout coil 7. The plates 8, and the associated arc shield, are secured to the blowout coil by means of a bolt 12.

Each of the movable contact; members 4. is pivotally mounted on a bracket 13 and is provided with a spring 14 which is compressed when the switch is closed to maintain the movable contact members in yielding engagement with the stationary contact members. The brackets 13 are mounted on opposite ends of an insulated bar 15 which is actuated by the electromagnet device 5. Energy is conducted to the movable contactmembers 4 by means of terminal members 16 and associated connecting leads 17.

The electromagnet actuating device 5 comprises a core member 18,2. coil 19 for exciting the core member, an armature 20 that is adapted to coact with the core member 18, and an armaturesupporting member 21 that is pivotally mounted on the core member and on the armature.

The core -member 18 comprises similar unitary members 22 and 23 of laminated magnetic material that are clamped in o posed spaced relationship between .si e

plates of non-magnetic material by means of bolts Each of the unitary members 22 and 2 3 composed of a plurality of rigidly-assembled laminae of: magnetic material. B3 grouping tle members in opposed spaced relation, an air gap 2? is provided in the stationar portion of the mag netic circuit of the members 18.

Each oi the side plates 2 is provided with laterally extending lugs 28 and *2!) tor rigidlv mounting the core member on the panel and a laterally extending lug 30 for clamping the coil 19 in place. Longitudinallv-extending cars 31 constitute means tor pivotall v mountii'ig the armaturbo-supporting member 21 on the panel 3.

The coil 19 is mounted on one ot the core member 18 and is clamped in place by means 01 a bolt 32. The portions and 23 ot the core member are each provided with a pole face 33 which coacts with the arina ture 20. The faces 33 are disposed in substantially coincident planes.

The armature 20 is provided with pole faces 34: which coact with faces 33 ot the core member. A pivot is provided for pivotallv mounting the armature between depending side portions 36 ot the supporting member 21.

The enlarged central portion ot' the pivot 35 constitutes the bearing portion of the pivot for supporting the armature 20. The aperture for receiving the pivot 35 has a restricted portion 18 which engages the portion 37 ot the pivot 35. The edges of the enlarged portion 37 ot the pivot are sutficientlv rounded to permit of a limited universal movement of the armature 20 in order that the armature may be free seating or, in other words, to permit of the best possible engagement of the coacting faces 33 and 3%. Loosely fitting washers 39 position the armature between side portions 36 ot the sui iporting member 21.

The armature 20 is pivotallv mounted at its magnetic balance or in such manner that the forces of attraction of the opposite pole pieces give substantially equal and opposite turning movements .hout the pivotal support of the armature.

Depending side portions 36 of the member 21 constitute a iivotal mounting for the armature 20 and provide a box-like portion that partiall encloses the armature. Laterally extending lugs i0 pr vide means for mounting the insulated bar 15 on the supporting member ll. The portions ll of the supporting member 21 co-operate with lugs 31 of the core member 18 for pivotallv mounting the supporting member on the panel 3. A tail piece 42 engages the portion 22 oi the core member to limit the degree of opening of the electromagnetwhen coil 19 is deenergized.

By interposing the air gap 27 in the rigidl assembled portion of the core member 1% all chattering and noise that is incident to a structure in which the air gap is positinned between relatively movable parts, is avoided. This form oi? construction also enal the core member to be formed tron'i unit portions by assembling two such portu n opposed relation. This arrangement also greatlv reduces the expense of niamrlacture and provides a convenient and desirable shape of punching.

A iturther advantage of this structure is the ease with which proper seating ot the armatin'e niav be s cured. even though the relatively n'iovable parts are mechanically displaced.

After the core member 18 is rigidly assembled between side plates 2a, the core member is securely clamped in a grinding machine and the pole tnces 33 are ground to provide tacos that are disposed in sub stantially coincident plan The armature Q0 similarly constructed to provide faces 23-; that will properly engage 'laces 33 of the core member. Since the armature is provi ed with a pivotal mounting which permits ot a limited movement oi" the ari'nature member in three directions, it is not essential that the pivotal mounting e1 be so constructed that an exact mechanical positioning oil the armature results. The pivotal mounting will permit of a considerable degree of adjustments between the parts. Each core-engaging tace oi the armature 2O provided with a shading coil it for reducing the chattering ot' the armature member. The relative advantage of providing an armature and a core member with co-operating "laces which are so ground as to permit close engagement will be appreciated when it is pointed out, that, heretofore. it has been found necessarv to file the co-operating laces oi electromagnet devices. employed as this device is to be emploved. in order to insure proper engagement of the faces. lVith the best. obtainable term (it hand work. uniform and close engagement of the faces cannot be secured and noise and chattering of the electromagnet results. The positioning ot the air gap 27 in a stationary part of the magnetic path and the ewtremelv close co-operation of engaging pole faces insure a magnetic path in which the reluctance is substantially constant. hen the air gap of the electromagnetic device is positioned between relativelv movable parts, the reluctance of the magnetic path is changed with every alteration of the relation of the parts.

By providing the armature with shading coils at each core-engaging face. a damping action is secured at each juncture of relatively movable parts which reduces chattering and other noises incident to junctures of movable parts in the magnetic circuit that are not so arran ed. 7

Although we have escribed a simple and preferred form of our invention, we desire that only such limitations shall be imposed as are indicated in the appended claims.

We claim as our invention:

1. An electromagnet comprising a core member having an interposed air gap and a glurality of pole faces, and a magnetically ba anced armature adapted to coact with said pole faces, said faces being positioned in substantially parallel planes.

2. An electromagnet comprising a core member having an interposed air ga and a plurality of pole faces of unlike polarity, and a pivotally mounted and magnetically balanced armature adapted to engage said faces.

3. An electromagnet comprising a core member having an interposed air gap and a plurality of pole faces of unlike polarity, and a pivotally mounted and magnetically balanced armature ada ted to engage said faces, said faces being isposed in substantially coincident planes. 7

4. A magnetizable core member constituting a portion of a magnetic circuit, and an armature constituting an additional portion of said magnetic circuit, said armature being pivotally mounted at substantially the magnetic balance thereof.

5. A magnetizable core member having a plurality of armature-attracting portions. an armature adapted to be attracted by said portions, and a device actuated by the movement of said armature, said armature being pivotally connected to said device at a point substantially at the magnetic balance of said armature.

6. A magnetizable core member constituting a portion of a magnetic circuit, an armature constituting an additional portion of said magnetic circuit, a device actuated by e said armature, and pivotal means for connecting said armature to said device at substantially the magnetic balance of said armature.

' 7. An electromagnet comprising a magnetizable core member having an air gap disposed in the magnetic path intermediate the extremities of said core, a pivotally mounted armature constituting a portion of the magnetic path traversing said core member and magnetically balanced therein, a device actuated by said armature, and pivotal means disposed between the extremities of said armature for pivotally conmember of U-shape, an armature co-acting with the legs of said core member to complete amagnetic path, and a device actuated by said armature comprising a pivotally mounted box portion having depending side portions, said armature being pivotally mounted between said side portions.

10. An electromagnet comprising a core member, and an armature pivotally mounted at its magnetic balance and pivotally mounted on the core member.

11. An electromagnet comprising a core member having a plurality of armature-attracting faces, an armature coacting with said faces, a member pivotally mounted on said core member and pivotally supporting said armature at the magnetic balance of said armature.

12. The combination with an electromagnet com rising a core member having an air gap etween rigid portions thereof, of a magnetically balanced armature adapted to constitute a ortion of a magnetic circuit including said core member, and a shading coil associated with each portion of said magnetic circuit which traverses relatively movable parts.

13. An electromagnet comprising a magnetizable core member of U-shape having an air gap intermediate the extremities thereof, a magnetically balanced armature adapted to coact with the legs of said core member, and a plurality of shading coils disposed on said armature opposite the respective legs of said core member.

In testimony whereof We have hereunto subscribed our names this 10 day of February, 1920.

CHARLES H. HODGKINS. WALTER C. GOODWIN. 

